Pakistani volunteers carry an injured passenger following a bomb blast in Peshawar, Pakistan, Wednesday, March 16, 2016. A bomb ripped through a bus carrying Pakistani government employees in the northwestern city of Peshawar on Wednesday, killing a number of people, police said. (Photo by Mohammad Sajjad/AP Photo)

Israeli police inspectors stand next to a bus damaged in an explosion March 23, 2011 in Jersalem, Israel. A bomb exploded near a crowded bus, wounding passengers in what appeared to be the first militant attack in the city in several years.

A refugee sits in front of a Greek riot police cordon during a protest at the Greek-Macedonian border, near the Greek village of Idomeni, March 1, 2016. (Photo by Alexandros Avramidis/Reuters)

Magbola Alhadi, 20, and her three children pose for a portrait in Jamam refugee camp in Maban County, South Sudan on August 11th, 2012. Magboola and her family weathered aerial bombing raids for several months, but decided it was time to leave their village of Bofe the night that soldiers arrived and opened fire. With her three children, she travelled for 12 days from Bofe to the town of El Fudj, on the South Sudanese border. The most important thing that Magboola was able to bring with her is the saucepan she holds in this photograph. It wasn't the largest pot that she had in Bofe, but it was small enough she could travel with it, yet big enough to cook sorghum for herself and her three daughters (from left: Aduna Omar, 6, Halima Omar, 4, and Arfa Omar, 2) during their journey. (Photo by Brian Sokol/Panos Pictures)

An internally displaced girl stands on an abandoned railway tracks beside a makeshift refugee camp in Sinjar town, in Idlib province, Syria November 20, 2015. (Photo by Ammar Abdullah/Reuters)

32 year old Mahada Khatum repairs a fishing net outside her home in the Shamalapur Rohingya refugee settlement on April 11, 2014 in Chittagong district, Bangladesh. Some years ago she escaped violence and discrimination from the Zomgara Baharchara village in the Meherulla district of Myanmar. (Photo by Getty Images/Stringer)

Iraqi Kurdish refugees wait with children in Cukurca refugee camp in Turkey April 8, 1991. Reuters photographers have chronicled Kurdish refugee crises over the years. In 1991 Srdjan Zivulovic documented refugees in Cukurca who had escaped a military operation by Saddam Hussein's government in Iraq aimed at “Arabising” Kurdish areas in the north. Hundreds of thousands fled into Turkey and Iran. Images shot in recent months show familiar scenes as crowds of people flee Islamic State militants in Syria. There are as many as 30 million Kurds, spread through Turkey, Iraq, Syria and Iran. Most Kurds are Sunni Muslims, but tend to feel more loyalty to their Kurdishness, rather than their religion. (Photo by Srdjan Zivulovic/Reuters)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)